The US embassy in Cairo issued a security warning on Thursday, urging American citizens in Egypt to avoid protests planned for Friday.

The Muslim Brotherhood and other Islamist groups, including the centrist Wasat Party and the ultra-conservative Al-Gamaa Al-Islamiya, plan to hold a “million-man” march on Friday in Cairo’s Nasr City to denounce violence, which they accuse opposition groups of planning for an upcoming day of anti-government rallies on 30 June.

Anti-government protests are also taking place in Abbasiya in central Cairo, according to the embassy’s statement.

The statement also warned US citizens to avoid protests in Alexandria.

“Anti-government demonstrations are expected on Friday along the Corniche at Chatby, and pro-Islamist demonstrations in Sidi Bishr,” the statement read.

The embassy further warned their citizens about the possibility of “sporadic unannounced demonstrations” prior to 30 June.

Friday will also see a march by anti-Morsi activists in Imbaba, near downtown Cairo, followed by a conference involving the Egyptian Popular Current and several opposition groups. Attendees will discuss the current political situation and the planned 30 June protests against President Mohamed Morsi.

Activists marching on Friday are also planning to collect signatures for the 'Rebel' petition, a campaign which aims to collect 15 million signatures calling for early presidential elections by 30 June, the first anniversary of Morsi's presidency.

The US embassy, located close to Cairo's Tahrir Square, was the site of fierce clashes last September during protests against a US-made film that insulted Prophet Mohamed and Islam.

The clashes left at least two dead and over 220 injured.